


Our Sacred Duty

by ttme123



Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe, Anal Sex, Bottom Dimitri Alexandre Blaiddyd, Ceremonial Sex, Dimitri Alexandre Blaiddyd Needs a Hug, Dragon sex, Dragons, Dubious Consent, F/M, Fire Emblem Kink Meme, Immaculate One Rhea, Kink Meme, Mating Cycles/In Heat, Mentioned My Unit | Byleth, Rough Sex, Shameless Smut, Smut, felix and byleth both appear at the beginning, where rhea has a monthly heat and students have to relieve her
Language: English
Status: Completed
Published: 2020-07-06
Updated: 2020-07-06
Packaged: 2021-03-05 03:13:41
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,787
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25117444
Author URL: https://archiveofourown.org/users/ttme123/pseuds/ttme123
Summary: "So basically every month the Immaculate One goes into heat and the monastery holds a lottery to decide who gets to ease her of her burden, shall we say. This month, it's Dimitri's turn (again?!) And being a pious follower he understands it's part of his royal duty, but that doesn't mean he has to like it."~~~~~~~~~~~~~~~~~~Three Houses Kink Meme fill.
Relationships: Dimitri Alexandre Blaiddyd/Rhea
Comments: 4
Kudos: 42





	Our Sacred Duty

**Author's Note:**

> Fill for Kink Meme request:
> 
> "So basically every month the Immaculate One goes into heat and the monastery holds a lottery to decide who gets to ease her of her burden, shall we say. This month, it's Dimitri's turn (again?!) And being a pious follower he understands it's part of his royal duty, but that doesn't mean he has to like it.
> 
> I always headcanon the Immaculate One having a ribbed dragon cock if that's cool and I just think Dimitri is pretty and should be fucked and do his holy duty. Outside of that, I'm leaving the setup and how it goes down to you. Thanks <3"
> 
> I've never written anything remotely like this before, but I gave it my best attempt!

"Surely there must be some mistake, Professor. This is the third time in six months..."

Byleth shook their head, sympathy clear on their face, "Sorry, Dimitri. It's just bad luck."

"Isn't the entire point of your job to protect us students?! How can you let them do this to him; it's obviously rigged!" Felix stormed up to Byleth's podium in anger.

Dimitri reached out a hand, placatingly, "No, it's alright, Felix. This is my duty as a follower of the Church of Seiros, after all. The professor is right, it's only bad luck. Or perhaps it's a divine test of my devotion to the goddess."

Felix's lip curled in disgust as he turned to leave, muttering "Stubborn boar," as he shoved through the door.

Dimitri took a deep breath and released it.

"If you'll excuse me, Professor, I'd like to go ready myself in my quarters."

Byleth nodded their permission, and turned to take attendance for the coming lecture.

* * *

Dimitri steadied himself as he entered the Holy Mausoleum, the chamber where this ceremony would take place. Presumably so that they would have enough room, regardless of what kind of mood the Immaculate One was in.

Lady Rhea was already in the room, facing away from him towards the distant throne, dressed in a white shift and her headdress. She always wore her headdress during the start of the ceremony, though Dimitri wasn't sure why.

"Good afternoon, Lady Rhea," he said, as he wasn't sure if she had heard him enter.

She turned to him, a gentle smile on her face.

"Greeting, Prince Dimitri. I assume you are familiar with the process, by now?"

He blushed, "Ah, yes, I am. Should I begin undressing?"

She nodded, turning back to the throne to give him some semblance of privacy. Not that it would amount to much, but he supposed that perhaps her consciousness may not be entirely the same as that of the beast which he would soon be dealing with. Maybe her perception of him wasn’t entirely tainted, yet.

He found himself recalling the past two times that he had been selected for this process; he had been the very first student to "win" the lottery, this year, and he’d been terrified the first time he was lead into the underground chamber. He was chosen again just last month, and, frankly, had been hoping that that would mean he was guaranteed a break for a while. How wrong he had been.

"Are you ready, Dimitri?" Lady Rhea called out to him, had walked over to now stand in front of him, and he had been too lost in thought to notice.

"Er, yes, Lady Rhea. I'm ready when you are."

"Would you like to prepare yourself again this time?" She gestured to the bottle of lubricant that had been provided to them. For his benefit, of course.

"Yes, I'll try to be quicker this time," after experiencing the embarrassment of having the Archbishop finger his asshole that first time, when he was too nervous and unsure of how to prepare himself, he had last month chosen to undergo the process on his own, but in his efforts to avoid the pain, had taken too long and nearly caused Lady Rhea to lose control.

This time, Dimitri wasted no time in slicking up the first finger and pushing right in. As soon as he was sure that his inside was sufficiently oiled up, he pushed in the second finger, wincing in slight discomfort. He tried to wiggle the two fingers, even scissoring them apart, in the hopes of stretching himself enough that he could at least handle Lady Rhea's initial girth. Taking a glance at the Archbishop again, who was smiling politely as she watched him get ready, he forced in a third finger, now feeling uncomfortably tight. Knowing that time was short, he thrust the fingers in and out a few times, ensuring that he was as slicked up and stretched out as he could manage.

He pulled his fingers out with a sigh of relief, "Okay, I think I'm ready."

She handed him a small towel to wipe his hand off with, which he used, then tossed aside with the oil.

"Are you going to get in position?" She reminded him, as she used the lubricant to slick up her swollen cock. He blushed.

"Oh, yes, my apologies." He fumbled awkwardly to his hands and knees on the thin blanket which had been laid out for them. For him.

He could feel her approach him from behind, "You seem distracted today, Dimitri. Is something the matter?" She knelt between his spread legs. His head hanging, he could see her milky thighs past his own shaking legs, and how red and swollen her dick already was.

"N-not at all, Lady Rhea." He had meant to give an excuse, that he was just lost in thought, but he caught his breath as he felt her hands pry his ass cheeks apart to have better access to his entrance.

She hummed in response and pushed, slowly but firmly, into his waiting hole.

Dimitri kept his breath held in as he felt her ridged cock stretch him, deeper and deeper, until her hips finally rested against his rear. He let it all out with a ‘whoosh,’ and felt Rhea’s long, silky hair brush his back as she leaned over him, giving him a moment to adjust.

When the stinging had more or less subsided, he nodded, and had almost prepared himself for the rough pace she immediately took up, hips pistoning back and forth as she let herself surrender to her rut.

Dimitri clenched his eyes shut, breathing through his teeth as he felt her ridges catch on the rim of his hole every time she thrust in and out. He could feel the sweat begin to form on his brow as his arms struggled to hold his weight under Rhea’s brutal force.

He could hear her breathing become ragged, sounding more and more like growling, just as he could feel the cock inside of him grow longer and thicker, only some magical force keeping his body from tearing apart.

Finally, the Immaculate One roared as it gripped the young prince in its claw, pulling him bodily in time with the horrible trusts. Blood ran down his arms from the rough handling of his shoulder, and he could feel the exact moment that his arms gave out and his chest briefly hit the ground, before the dragon was sitting back, pulling him upwards until he was essentially sat on its massive dick.

Dimitri gasped at the new position; her cock felt so much deeper inside of him now, and the ridges felt as though they were scraping him raw from the inside out. He reached out, trying to find purchase on some part of her draconic form, but all he could do was hold onto the claw which was gripping his shoulder.

He knew from experience just how much longer this rut could last.

It was when he felt the clawed hand grasp, tearing open his flesh even more, that he knew her first orgasm was coming. He tried to brace himself, but was still overwhelmed by the sensation of her semen filling, filling him up until there was nowhere to go, his stomach distending, he could have sworn he felt it climb up his throat—and she flipped them over and pulled out.

On his stomach now, his ass still up in the air thanks only to his wobbly knees, Dimitri could feel the warm fluid gush out of his behind, running down the back of his thighs. His stomach deflated, and he hated the way his ass felt empty without her dick inside.

He didn’t have to wait long, as the Immaculate One quickly recovered and shoved its aching, swollen member back inside his abused hole, claw coming down on his back to hold him down—as if he had the energy to struggle, anyways.

He could feel the breath being forced from his body by the impossible strength of the beast rutting, humping obsessively into him like the animal it truly was. All Dimitri could do was groan, hands weakly flexing and toes curling as the pressure of the huge cockhead rammed into his prostate time and time again. The pain was so intense, and yet whatever magic that allowed the Immaculate One to breed humans without killing them also allowed him some disconnect from the pain, and kept the mild bursts of pleasure at the forefront of his mind.

Dimitri had to remind himself that he had survived this dragon’s rut twice before, he would survive this time, but as he felt the pressure on his back increase, he found himself struggling to pull in breath. Weirdly enough, it was this lightheaded asphyxiation which ultimately pushed him over the edge; every time the ridges passed through the rim of his over-stretched anus it sent shocks of pleasure, not pain, through his body, and combined with the rhythmic pushing against his prostate and the dizziness of too little oxygen, his body suddenly tensed up, his vision went white, and he could feel ropes of his cum spurt onto his belly, running down towards his bruised chest. He shuddered as waves of pleasure rolled through him, still all-too-aware of the beast fucking him from behind.

Exhausted, Dimitri let himself go limp, body rocking back and forth as the Immaculate One used him for its own pleasure. He felt disconnected from his body, the pain and the weariness only indirectly related to him, like watching the scene from an outsider’s perspective. He only came back to himself when he felt the draconic body behind him begin to shrink, the knot inside of him shrinking, in turn, to a much more reasonable size. Still not small enough to let out the cum which filled him, but a relief all the same.

He didn’t realize that he had fallen asleep until he found himself waking up to the sight of Lady Rhea’s worried face, her hair draped around his own head as she pet his cheek and looked into his eyes to check if he was alright. He was pretty sure he was laying on the blanket, the soft fabric against the scrapes on his back feeling only half as painful as his rear-end.

“Are you feeling alright, my child?”

Dimitri nodded, head rolling to the side as he struggled to sit up. Rhea’s gentle hands helped prop him up. He could see her headdress, abandoned where it had rolled an hour ago when she transformed.

He really hoped this would be the last time his name was selected in the lottery.

**Author's Note:**

> I don't usually write (or even read) any monsterfucking or beastial stuff, but I saw this prompt and just had to try it. If you enjoyed, please give kudos and leave comments! They really mean a lot!
> 
> (tumblr: [gaymageclub](http://gaymageclub.tumblr.com/)
> 
> twitter: [anarchygay](https://twitter.com/anarchygay))


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